[SDL] Enemy class inheriting from tile class.

This is a discussion on [SDL] Enemy class inheriting from tile class. within the Game Programming forums, part of the General Programming Boards category; I'm trying to learn how to make an enemy class inherit from a tile class to use with a level ...

  1. #1
    Registered User Kain's Avatar
    Join Date
    Nov 2012
    Posts
    17

    [SDL] Enemy class inheriting from tile class.

    I'm trying to learn how to make an enemy class inherit from a tile class to use with a level editor that places tiles. However, I'm still very new to programming, and I probably don't know how to use inheritance correctly.

    Here is the code:

    Code:
    class tile
    {
        private:
    
        SDL_Rect box;
        int type;
    
        public:
    
        tile( int x , int y , int ttype );
        void show();
        int gettype();
        SDL_Rect getbox();
    };
    
    class enemy : public tile
    {
        private:
    
        SDL_Rect box;
        int type;
    
        public:
    
        enemy( int x , int y , int ttype ) : tile( x , y , ttype ) {}
        void move( tile * tiles );
        void show( tile * tiles );
    };
    
    
    ...
    
    
    void enemy::move( tile * tiles )
    {
        int velx = 0;
        int vely = 0;
        vely += gravity;
        velx += 10;
        box.y += vely;
        box.x += velx;
    
        if( col( box , &tiles ) == true )
        {
            box.x -= velx;
            box.y -= vely;
        }
    }
    
    void enemy::show( tile * tiles )
    {
        if( col( camera , box ) == true )
        {
            apply( box.x , box.y , enemy , screen );
        }
        move( tiles );
    }
    ...In the editor...:

    Code:
    bool settiles( tile * tiles[] )
    {
    
    ...
    
            if( ( ttype >= 0 ) && ( ttype < PLATFORM ) )
            {
                tiles[t] = new tile( x , y , ttype );
            }
            else if( ttype == ENEMY )
            {
                tiles[t] = new enemy( x , y , ttype );
            }
    
    ...
    ...And in the main loop:

    Code:
    int main( int argc , char * argv[] )
    {
        bool quit = false;
    
        tile * tiles[TT];
    
    ...
    
        while( quit == false )
        {
    
    ...
    
            for( int t = 0 ; t < TT ; t++ )
            {
                tiles[t]->show();
                tiles[t]->enemy::show( tiles[t] );
            }
    
    ...
    I have tried many different approaches, but I can't seem to get it right.
    This particular approach gives me this error at the main loop:

    Code:
    error: 'enemy' is not a base of 'tile'
    Can anyone give me some advice on how to get this right?

    I'm using LazyFoo's tutorials, by the way.

    Thank you in advance! :-)

  2. #2
    Super Moderator VirtualAce's Avatar
    Join Date
    Aug 2001
    Posts
    9,596
    An enemy is certainly not a tile. An enemy is a separate entity and is more likely a sprite on the tile map than a tile itself. I would also caution the use of an enemy class. Remember that classes define behaviors not roles.

  3. #3
    Registered User Kain's Avatar
    Join Date
    Nov 2012
    Posts
    17
    I see what you mean. The only reason I want to make an enemy class is that I want to make an enemy editor.

    I made a seperate editor with a seperate map just for enemies, and it seems to work fime, but I don't know where to place the move function for the enemy class. Wherever I try placing it, it returns 3.

    Here is the code:

    Code:
    void enemy::move( tile * tiles[] )
    {
        xvel = -10;
        box.x += xvel;
    
        if( col( box , tiles ) == true )
        {
            box.x -= xvel;
        }
    
        box.y += yvel;
    
        if( col( box , tiles ) == true )
        {
            if( yvel >= 0 )
            {
                box.y -= yvel - ( TH % yvel );
                yvel = 0;
            }
            else
            {
                box.y -= yvel;
                yvel = 0;
            }
        }
    
        yvel += gravity;
    }
    ...Practically a copy of the player sprite's movement, minus the controls.

    I have tried this:

    Code:
    for( int e = 0 ; e < TT ; e++ )
    {
         enemies[e]->move( tiles );
    }
    ...In the main loop, and I have also tried placing the move function inside the enemies' show() function, with the same result.

    When I don' use the move function everything works fine ( except of course that the enemy is not moving ).

    Is it because I use a seperate map file for the enemies?
    Last edited by Kain; 01-18-2013 at 07:22 AM.

  4. #4
    Registered User
    Join Date
    Jan 2013
    Location
    UK
    Posts
    19
    I can't see anything. Could you not upload the full source to something like sourceforge

  5. #5
    Registered User Kain's Avatar
    Join Date
    Nov 2012
    Posts
    17
    Sorry for the delay, it took me some time to re-write thw code in a readable fashion.
    I'm not familiar with SourceForge yet, though, so I'll upload it here if it's not a problem. :-)

    globals.h
    Code:
    #ifndef GLOBALS_H_INCLUDED
    #define GLOBALS_H_INCLUDED
    
    const int SCREEN_WIDTH = 640;
    const int SCREEN_HEIGHT = 480;
    const int BITS_PER_PIXEL = 32;
    const int FPS = 12;
    
    const int TILE_WIDTH = 50;
    const int TILE_HEIGHT = 50;
    
    const int TILES_ROW = 16;
    const int TILES_COLUMN = 12;
    
    int TOTAL_TILES = TILES_ROW * TILES_COLUMN;
    
    int LEVEL_WIDTH = TILES_ROW * TILE_WIDTH;
    int LEVEL_HEIGHT = TILES_COLUMN * TILE_HEIGHT;
    
    const int TILE_SPRITES = 3;
    const int ENEMY_SPRITES = 2;
    
    const int PLAYER_WIDTH = 50;
    const int PLAYER_HEIGHT = 100;
    
    const int gravity = 10;
    
    enum
    {
        FACING_RIGHT,
        FACING_LEFT
    };
    
    SDL_Surface * screen = NULL;
    SDL_Surface * background = NULL;
    SDL_Surface * playersprite = NULL;
    SDL_Surface * tilesheet = NULL;
    
    SDL_Rect camera = { 0 , 0 , SCREEN_WIDTH , SCREEN_HEIGHT };
    
    SDL_Event event;
    
    #endif // GLOBALS_H_INCLUDED
    startup.h
    Code:
    #ifndef STARTUP_H_INCLUDED
    #define STARTUP_H_INCLUDED
    
    #include <fstream>
    #include "globals.h"
    
    int backgroundx = 0;
    int backgroundy = 0;
    
    SDL_Surface * enemysheet = NULL;
    
    bool init()
    {
        if( SDL_Init( SDL_INIT_EVERYTHING ) == -1 ) return false;
    
        screen = SDL_SetVideoMode( SCREEN_WIDTH , SCREEN_HEIGHT , BITS_PER_PIXEL , SDL_HWSURFACE | SDL_DOUBLEBUF );
    
        if( screen == NULL ) return false;
    
        SDL_WM_SetCaption( "Game" , NULL );
    
        return true;
    }
    
    SDL_Surface * load( std::string file )
    {
        SDL_Surface * loaded = NULL;
        SDL_Surface * optimized = NULL;
    
        loaded = IMG_Load( file.c_str() );
    
        if( loaded != NULL )
        {
            optimized = SDL_DisplayFormatAlpha( loaded );
            SDL_FreeSurface( loaded );
        }
    
        return optimized;
    }
    
    bool load_files()
    {
        enemysheet = load( "enemies.png" );
    
        if( enemysheet == NULL ) return false;
    
        background = load( "clouds.png" );
        playersprite = load( "sprite.png" );
        tilesheet = load( "tiles.png" );
        enemysheet = load( "enemy.png" );
    
        if( background == NULL || playersprite == NULL || tilesheet == NULL || enemysheet == NULL ) return false;
    
        return true;
    }
    
    void cleanup()
    {
        SDL_FreeSurface( enemysheet );
    
        SDL_FreeSurface( background );
        SDL_FreeSurface( playersprite );
        SDL_FreeSurface( tilesheet );
        SDL_FreeSurface( enemysheet );
    
        SDL_Quit();
    }
    
    void apply_surface( int x , int y , SDL_Surface * get = NULL , SDL_Surface * returned = NULL , SDL_Rect * clips = NULL )
    {
        SDL_Rect offsets;
    
        offsets.x = x;
        offsets.y = y;
    
        SDL_BlitSurface( get , clips , returned , &offsets );
    }
    
    void apply_surface( int x , int y , SDL_Surface * get , SDL_Surface * returned , int clipsx , int clipsy , int w , int h )
    {
        SDL_Rect offsets;
    
        offsets.x = x;
        offsets.y = y;
    
        SDL_Rect clips;
    
        clips.x = clipsx;
        clips.y = clipsy;
        clips.w = w;
        clips.h = h;
    
        SDL_BlitSurface( get , &clips , returned , &offsets );
    }
    
    bool collision( SDL_Rect a , SDL_Rect b )
    {
        int lefta , leftb;
        int righta , rightb;
        int topa , topb;
        int bottoma , bottomb;
    
        lefta = a.x;
        righta = a.x + a.w;
        topa = a.y;
        bottoma = a.y + a.h;
    
        leftb = b.x;
        rightb = b.x + b.w;
        topb = b.y;
        bottomb = b.y + b.h;
    
        if( righta <= leftb || lefta >= rightb || bottoma <= topb || topa >= bottomb ) return false;
    
        return true;
    }
    
    void scrolling_background()
    {
        backgroundx -= 1;
    
        if( backgroundx <= -background->w ) backgroundx = 0;
    
        apply_surface( backgroundx , backgroundy , background , screen );
        apply_surface( backgroundx + background->w , backgroundy , background , screen );
    }
    
    #endif // STARTUP_H_INCLUDED
    timer.h
    Code:
    #ifndef TIMER_H_INCLUDED
    #define TIMER_H_INCLUDED
    
    class timer
    {
        private:
    
        int start_ticks;
        bool started;
    
        public:
    
        timer();
        void start();
        int get_ticks();
    };
    
    timer::timer()
    {
        start_ticks = 0;
        started = false;
    }
    
    void timer::start()
    {
        started = true;
        start_ticks = SDL_GetTicks();
    }
    
    int timer::get_ticks()
    {
        if( started )
        {
            return SDL_GetTicks() - start_ticks;
        }
    
        return 0;
    }
    
    #endif // TIMER_H_INCLUDED
    player.h
    Code:
    #ifndef PLAYER_H_INCLUDED
    #define PLAYER_H_INCLUDED
    
    #include "SDL/SDL.h"
    #include "SDL/SDL_image.h"
    #include "tiles.h"
    #include "timer.h"
    
    class player
    {
        private:
    
        SDL_Rect box;
        int x;
        int y;
        int xvel;
        int yvel;
        bool jumping;
        int frame;
        int status;
    
        public:
    
        player( int X , int Y );
        void control();
        void jump();
        void move( tile * tiles[] );
        void player_camera();
        void show();
    };
    
    player::player( int X , int Y )
    {
        x = X;
        y = Y;
        xvel = 0;
        yvel = 0;
        jumping = false;
        frame = 0;
        status = FACING_RIGHT;
    
        box.x = x;
        box.y = y;
        box.w = PLAYER_WIDTH;
        box.h = PLAYER_HEIGHT;
    }
    
    void player::control()
    {
        if( event.type == SDL_KEYDOWN )
        {
            switch( event.key.keysym.sym )
            {
                case SDLK_d:
                xvel += PLAYER_WIDTH / 4;
                break;
    
                case SDLK_a:
                xvel -= PLAYER_WIDTH / 4;
                break;
    
                default: {}
            }
        }
    
        if( event.type == SDL_KEYUP )
        {
            switch( event.key.keysym.sym )
            {
                case SDLK_d:
                xvel -= PLAYER_WIDTH / 4;
                break;
    
                case SDLK_a:
                xvel += PLAYER_WIDTH / 4;
                break;
    
                default: {}
            }
        }
    }
    
    void player::jump()
    {
        Uint8 * keystate = SDL_GetKeyState( NULL );
    
        if( keystate[ SDLK_SPACE ] && jumping == false )
        {
            jumping = true;
            yvel = -50;
        }
    }
    
    void player::move( tile * tiles[] )
    {
        box.x += xvel;
    
        if( box.x < 0 || box.x + PLAYER_WIDTH > LEVEL_WIDTH || collision( box , tiles ) ) box.x -= xvel;
    
        box.y += yvel;
    
        if( collision( box , tiles ) && yvel >= gravity ) jumping = true;
    
        if( collision( box , tiles ) )
        {
            if( jumping && yvel >= 0 ) jumping = false;
    
            if( yvel >= 0 ) box.y -= yvel - ( TILE_HEIGHT % yvel );
            else box.y -= yvel;
    
            yvel = 0;
        }
    
        yvel += gravity;
    
        if( yvel >= gravity * 5 ) yvel = gravity * 5;
    
        if( box.y > LEVEL_HEIGHT + 50 )
        {
            box.y = 0;
            box.x = 0;
            status = FACING_RIGHT;
        }
    
        x = box.x;
        y = box.y;
    }
    
    void player::player_camera()
    {
        camera.x = ( x + PLAYER_WIDTH / 2 ) - SCREEN_WIDTH / 2;
        camera.y = ( y + PLAYER_HEIGHT / 2 ) - SCREEN_HEIGHT / 2;
    
        if( camera.x < 0 ) camera.x = 0;
        if( camera.x > LEVEL_WIDTH - camera.w ) camera.x = LEVEL_WIDTH - camera.w;
        if( camera.y < 0 ) camera.y = 0;
        if( camera.y > LEVEL_HEIGHT - camera.h ) camera.y = LEVEL_HEIGHT - camera.h;
    }
    
    void player::show()
    {
        if( xvel < 0 )
        {
            status = FACING_LEFT;
            frame++;
        }
        else if( xvel > 0 )
        {
            status = FACING_RIGHT;
            frame++;
        }
        else frame = 0;
    
        if( frame >= 4 ) frame = 0;
    
        if( status == FACING_RIGHT ) apply_surface( x - camera.x , y - camera.y , playersprite , screen , frame * PLAYER_WIDTH , 0 , PLAYER_WIDTH , PLAYER_HEIGHT );
        else if( status == FACING_LEFT ) apply_surface( x - camera.x , y - camera.y , playersprite , screen , frame * PLAYER_WIDTH , PLAYER_HEIGHT , PLAYER_WIDTH , PLAYER_HEIGHT );
    }
    
    #endif // PLAYER_H_INCLUDED
    tiles.h
    Code:
    #ifndef TILES_H_INCLUDED
    #define TILES_H_INCLUDED
    
    #include "globals.h"
    #include "startup.h"
    
    enum
    {
        NONE,
        BLUE,
        PLATFORM
    };
    
    class tile
    {
        private:
    
        SDL_Rect box;
        int tiletype;
    
        public:
    
        tile( int x , int y , int type );
        void show();
        int get_type();
        SDL_Rect get_box();
    };
    
    tile::tile( int x , int y , int type )
    {
        box.x = x;
        box.y = y;
        box.w = TILE_WIDTH;
        box.h = TILE_HEIGHT;
    
        tiletype = type;
    }
    
    void tile::show()
    {
        if( collision( camera , box ) )
        {
            apply_surface( box.x - camera.x , box.y - camera.y , tilesheet , screen , tiletype * TILE_WIDTH , 0 , TILE_WIDTH , TILE_HEIGHT );
        }
    }
    
    int tile::get_type()
    {
        return tiletype;
    }
    
    SDL_Rect tile::get_box()
    {
        return box;
    }
    
    void cleanup( tile * tiles[] )
    {
        for( int t = 0 ; t < TOTAL_TILES ; t++ ) delete tiles[t];
    
        cleanup();
    }
    
    bool collision( SDL_Rect a , tile * tiles[] )
    {
        for( int t = 0 ; t < TOTAL_TILES ; t++ )
        {
            if( tiles[t]->get_type() == PLATFORM )
            {
                if( collision( a , tiles[t]->get_box() ) ) return true;
            }
        }
    
        return false;
    }
    
    bool set_tiles( tile * tiles[] )
    {
        int x = 0;
        int y = 0;
    
        std::ifstream map( "tilemap.map" );
    
        if( map == NULL ) return false;
    
        for( int t = 0 ; t < TOTAL_TILES ; t++ )
        {
            int type = 0;
            map >> type;
    
            if( map.fail() )
            {
                map.close();
                return false;
            }
    
            if( type >= 0 && type < TILE_SPRITES ) tiles[t] = new tile( x , y , type );
            else
            {
                map.close();
                return false;
            }
    
            x += TILE_WIDTH;
    
            if( x >= LEVEL_WIDTH )
            {
                x = 0;
                y += TILE_HEIGHT;
            }
        }
    
        map.close();
        return true;
    }
    
    #endif // TILES_H_INCLUDED
    tileeditor.h
    Code:
    #ifndef TILEEDITOR_H_INCLUDED
    #define TILEEDITOR_H_INCLUDED
    
    #include "startup.h"
    
    int current_tile = NONE;
    
    void editor_camera()
    {
        int x = 0;
        int y = 0;
    
        SDL_GetMouseState( &x , &y );
    
        if( x < TILE_WIDTH ) camera.x -= 20;
        if( x > SCREEN_WIDTH - TILE_WIDTH ) camera.x += 20;
        if( y < TILE_HEIGHT ) camera.y -= 20;
        if( y > SCREEN_HEIGHT - TILE_HEIGHT ) camera.y += 20;
        if( camera.x < 0 ) camera.x = 0;
        if( camera.y < 0 ) camera.y = 0;
        if( camera.x > LEVEL_WIDTH - camera.w ) camera.x = LEVEL_WIDTH - camera.w;
        if( camera.y > LEVEL_HEIGHT - camera.h ) camera.y = LEVEL_HEIGHT - camera.h;
    }
    
    void editor_put_tiles( tile * tiles[] , int type )
    {
        int x = 0;
        int y = 0;
    
        SDL_GetMouseState( &x , &y );
    
        x += camera.x;
        y += camera.y;
    
        for( int t = 0 ; t < TOTAL_TILES ; t++ )
        {
            SDL_Rect box = tiles[t]->get_box();
    
            if( x > box.x && x < box.x + box.w && y > box.y && y < box.y + box.h )
            {
                delete tiles[t];
                tiles[t] = new tile( box.x , box.y , type );
            }
        }
    }
    
    bool editor_set_tiles( tile * tiles[] )
    {
        int x = 0;
        int y = 0;
    
        std::ifstream map( "tilemap.map" );
    
        if( map == NULL )
        {
            for( int t = 0 ; t < TOTAL_TILES ; t++ )
            {
                tiles[t] = new tile( x , y , NONE );
                x += TILE_WIDTH;
    
                if( x >= LEVEL_WIDTH )
                {
                    x = 0;
                    y += TILE_HEIGHT;
                }
            }
        }
        else
        {
            for( int t = 0 ; t < TOTAL_TILES ; t++ )
            {
                int type = 0;
                map >> type;
    
                if( map.fail() )
                {
                    map.close();
                    return false;
                }
    
                if( type >= 0 && type < TILE_SPRITES ) tiles[t] = new tile( x , y , type );
                else
                {
                    map.close();
                    return false;
                }
    
                x += TILE_WIDTH;
    
                if( x >= LEVEL_WIDTH )
                {
                    x = 0;
                    y += TILE_HEIGHT;
                }
            }
    
            map.close();
        }
    
        return true;
    }
    
    void editor_save( tile * tiles[] )
    {
        std::ofstream map( "tilemap.map" );
    
        for( int t = 0 ; t < TOTAL_TILES ; t++ ) map << tiles[t]->get_type() << " ";
    
        map.close();
    }
    
    void editor_show( int tiletype )
    {
        apply_surface( 20 , 20 , tilesheet , screen , tiletype * TILE_WIDTH , 0 , TILE_WIDTH , TILE_HEIGHT );
    }
    
    void editor_control( tile * tiles[] )
    {
        if( event.type == SDL_MOUSEBUTTONDOWN )
        {
            if( event.button.button == SDL_BUTTON_LEFT ) editor_put_tiles( tiles , current_tile );
            else if( event.button.button == SDL_BUTTON_RIGHT ) editor_put_tiles( tiles , NONE );
            else if( event.button.button == SDL_BUTTON_WHEELUP )
            {
                current_tile--;
    
                if( current_tile < NONE ) current_tile = PLATFORM;
    
                editor_show( current_tile );
            }
            else if( event.button.button == SDL_BUTTON_WHEELDOWN )
            {
                current_tile++;
    
                if( current_tile > PLATFORM ) current_tile = NONE;
    
                editor_show( current_tile );
            }
        }
    }
    
    #endif // TILEEDITOR_H_INCLUDED
    enemies.h
    Code:
    #ifndef ENEMIES_H_INCLUDED
    #define ENEMIES_H_INCLUDED
    
    #include "globals.h"
    #include "startup.h"
    
    enum
    {
        NO_ENEMY,
        BUBBLE
    };
    
    class enemy
    {
        private:
    
        SDL_Rect box;
        int enemytype;
        int x;
        int y;
        int xvel;
        int yvel;
        int status;
    
        public:
    
        enemy( int X , int Y , int type );
        void show();
        void move( tile * tiles[] );
        int get_type();
        SDL_Rect get_box();
    };
    
    enemy::enemy( int X , int Y , int type )
    {
        x = X;
        y = Y;
        xvel = 0;
        yvel = 0;
        enemytype = type;
        status = FACING_LEFT;
    
        box.x = x;
        box.y = y;
        box.w = TILE_WIDTH;
        box.h = TILE_HEIGHT;
    }
    
    void enemy::show()
    {
        if( collision( camera , box ) ) apply_surface( box.x - camera.x , box.y - camera.y , enemysheet , screen , enemytype * TILE_WIDTH , 0 , TILE_WIDTH , TILE_HEIGHT );
    }
    
    void enemy::move( tile * tiles[] )
    {
        if( status == FACING_LEFT ) xvel = -10;
        else xvel = 10;
    
        box.x += xvel;
    
        if( collision( box , tiles ) )
        {
            box.x -= xvel;
    
            if( status == FACING_LEFT ) status = FACING_RIGHT;
            else status = FACING_LEFT;
        }
    
        box.y += yvel;
    
        if( collision( box , tiles ) )
        {
            if( yvel <= 0 ) box.y -= yvel - ( TILE_HEIGHT % yvel );
            else box.y -= yvel;
    
            yvel = 0;
        }
    
        yvel += gravity;
    }
    
    int enemy::get_type()
    {
        return enemytype;
    }
    
    SDL_Rect enemy::get_box()
    {
        return box;
    }
    
    #endif // ENEMIES_H_INCLUDED
    game.h
    Code:
    #ifndef GAME_H_INCLUDED
    #define GAME_H_INCLUDED
    
    #include "SDL/SDL.h"
    #include "SDL/SDL_image.h"
    #include <string>
    #include "startup.h"
    #include "timer.h"
    #include "player.h"
    #include "tileeditor.h"
    
    #include "enemyeditor.h"
    
    int game()
    {
        bool quit = false;
        bool tileedit = false;
    
        if( init() == false ) return 1;
        if( load_files() == false ) return 2;
    
        timer fps;
        player player1( 50 , 50 );
        tile * tiles[ TOTAL_TILES ];
        enemy * enemies[ TOTAL_TILES ];
    
        if( set_tiles( tiles ) == false ) return 4;
    
        while( quit == false )
        {
            fps.start();
            scrolling_background();
            if( tileedit ) editor_show( current_tile );
    
            while( SDL_PollEvent( &event ) )
            {
                if( event.type == SDL_KEYDOWN )
                {
                    if( event.key.keysym.sym == SDLK_t ) tileedit = !tileedit;
                }
    
                if( event.type == SDL_QUIT ) quit = true;
    
                if( tileedit == false ) player1.control();
                else if( tileedit ) editor_control( tiles );
            }
    
            if( tileedit == false )
            {
                player1.jump();
                scrolling_background();
                player1.move( tiles );
                player1.player_camera();
            }
            else editor_camera();
    
            for( int t = 0 ; t < TOTAL_TILES ; t++ ) tiles[t]->show();
            for( int e = 0 ; e < TOTAL_TILES ; e++ ) enemies[e]->show();
            if( tileedit == false ) player1.show();
    
            if( SDL_Flip( screen ) == -1 ) return 5;
    
            if( fps.get_ticks() < 1000 / FPS ) SDL_Delay( ( 1000 / FPS ) - fps.get_ticks() );
        }
    
        editor_save( tiles );
        cleanup( tiles );
        cleanup( enemies );
    
        return 0;
    }
    
    #endif // GAME_H_INCLUDED
    main.cpp
    Code:
    #include "game.h"
    
    int main( int argc , char * argv[] )
    {
        game();
    
        return 0;
    }
    enemyeditor.h
    Code:
    #ifndef ENEMYEDITOR_H_INCLUDED
    #define ENEMYEDITOR_H_INCLUDED
    
    #include "enemies.h"
    
    void cleanup( enemy * enemies[] )
    {
        for( int e = 0 ; e < TOTAL_TILES ; e++ ) delete enemies[e];
    }
    
    bool collision( SDL_Rect a , enemy * enemies[] )
    {
        for( int e = 0 ; e < TOTAL_TILES ; e++ )
        {
            if( enemies[e]->get_type() == BUBBLE )
            {
                if( collision( a , enemies[e]->get_box() ) ) return true;
            }
        }
    
        return false;
    }
    
    bool set_enemies( enemy * enemies[] )
    {
        int x = 0;
        int y = 0;
    
        std::ifstream map( "enemymap.map" );
    
        if( map == NULL ) return false;
    
        for( int e = 0 ; e < TOTAL_TILES ; e++ )
        {
            int type = 0;
            map >> type;
    
            if( map.fail() )
            {
                map.close();
                return false;
            }
    
            if( type >= 0 && type < ENEMY_SPRITES ) enemies[e] = new enemy( x , y , type );
            else
            {
                map.close();
                return false;
            }
    
            x += TILE_WIDTH;
    
            if( x >= LEVEL_WIDTH )
            {
                x = 0;
                y += TILE_HEIGHT;
            }
        }
    
        map.close();
        return true;
    }
    
    #endif // ENEMYEDITOR_H_INCLUDED
    If you want I could upload the whole thing, sprites, maps and everything, compressed in a .rar file to have a better look at. :-)

    The problem seems to be at the last file, enemyeditor.h
    Before I made the program read enemies from an enemy map, I tried creating an enemy entity manually and it worked perfectly.
    But ever since I made it read enemies from a map, it returns 3.
    enemyeditor.h is practically a copy of the functions that read tiles from a map file.
    I did not write the editor functions for the enemies yet, since the problem is at reading the enemy map.

    I am pretty new at programming in general, as I already said, so I'm not sure if this is even the right approach to make an enemy placement program to place enemies on the map just like I'm placing tiles.

    Any help would be appreciated.

    Thank you in advance. :-)

  6. #6
    Registered User Kain's Avatar
    Join Date
    Nov 2012
    Posts
    17
    I'm so sorry for the double post, but it seems I cannot edit my previous one.

    So, it seems I made a mistake in my last post. The program was crashing because I forgot to call the set_enemies function. The correct code for game.h is this:

    game.h
    Code:
    #ifndef GAME_H_INCLUDED
    #define GAME_H_INCLUDED
    
    #include "SDL/SDL.h"
    #include "SDL/SDL_image.h"
    #include <string>
    #include "startup.h"
    #include "timer.h"
    #include "player.h"
    #include "tileeditor.h"
    
    #include "enemyeditor.h"
    
    int game()
    {
        bool quit = false;
        bool tileedit = false;
    
        if( init() == false ) return 1;
        if( load_files() == false ) return 2;
    
        timer fps;
        player player1( 50 , 50 );
        tile * tiles[ TOTAL_TILES ];
        enemy * enemies[ TOTAL_TILES ];
    
        if( set_tiles( tiles ) == false ) return 4;
        if( set_enemies( enemies ) == false ) return 4;
    
        while( quit == false )
        {
            fps.start();
            scrolling_background();
            if( tileedit ) editor_show( current_tile );
    
            while( SDL_PollEvent( &event ) )
            {
                if( event.type == SDL_KEYDOWN )
                {
                    if( event.key.keysym.sym == SDLK_t ) tileedit = !tileedit;
                }
    
                if( event.type == SDL_QUIT ) quit = true;
    
                if( tileedit == false ) player1.control();
                else if( tileedit ) editor_control( tiles );
            }
    
            if( tileedit == false )
            {
                player1.jump();
                scrolling_background();
                player1.move( tiles );
    
                //////////////////////////       PROBLEM IS HERE       //////////////////////////
    
                //for( int e = 0 ; e < TOTAL_TILES ; e++ ) enemies[e]->move( tiles );
    
                ///////////////////////////////////////////////////////////////////////////////////
    
                player1.player_camera();
            }
            else editor_camera();
    
            for( int t = 0 ; t < TOTAL_TILES ; t++ ) tiles[t]->show();
            for( int e = 0 ; e < TOTAL_TILES ; e++ ) enemies[e]->show();
            if( tileedit == false ) player1.show();
    
            if( SDL_Flip( screen ) == -1 ) return 5;
    
            if( fps.get_ticks() < 1000 / FPS ) SDL_Delay( ( 1000 / FPS ) - fps.get_ticks() );
        }
    
        editor_save( tiles );
        cleanup( tiles );
        cleanup( enemies );
    
        return 0;
    }
    
    #endif // GAME_H_INCLUDED
    As you can see, there seems to be a problem every time I try to call enemy::move(tile * tiles[])
    The debugger gives me a segmentation fault, wich, from what I understand, means that the function is trying to access the wrong piece of memory. I can't find where exactly is the problem though, so, once again, I need some help figuring it out.

    Sorry for asking so many things, and, as always, thank you in advance.

Popular pages Recent additions subscribe to a feed

Similar Threads

  1. Problem inheriting class getting infinite loop
    By joeba18 in forum C# Programming
    Replies: 3
    Last Post: 12-14-2010, 10:19 PM
  2. Using or inheriting a class
    By audinue in forum A Brief History of Cprogramming.com
    Replies: 2
    Last Post: 11-20-2008, 11:11 AM
  3. Class operators when inheriting
    By 39ster in forum C++ Programming
    Replies: 5
    Last Post: 07-14-2008, 06:13 AM
  4. Replies: 8
    Last Post: 10-02-2005, 12:27 AM
  5. inherited variables in template class not inheriting
    By fimion in forum C++ Programming
    Replies: 4
    Last Post: 06-01-2005, 08:10 AM

Tags for this Thread


1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21